sed command to replace if( with if ( [duplicate]

Question

This question already has answers here:

Find and replace in file and overwrite file doesn't work, it empties the file (12 answers)

Closed 9 years ago.

I want to run a sed command : sed command to replace if( with if (

My command looks like this:

sed 's/if(/if ( /g' file1.c >file1.c

where file1.c contains the string that needs to be replaced.

Problem is file contents gets cleared and no changes are reflected.

Answer 1

You can try two different approaches.

If you want to update existing file:

sed -i 's/if(/if ( /g' file1.c  

If you want to store the modified file in another file:

sed 's/if(/if ( /g' file1.c > file2.c  

Answer 2

Use this:

sed -re 's/if(/if ( /g'